Pulley and like element



F. -H. JOHNSTON AND J. C. CHRISTENSEN.

,PULLEY AND LIKE ELEMENT.

APPLICATION FILED OCT. I4. I9I8. I

Patented Feb. 17, 1920.

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UNITED STATES PATENT ()FFICE.

FRANK H. JOHNSTON AND JAMES o. CHRISTENSEN, or mmrmnroms, INDIANA.

' 'PUIJLEY AND LIKE ELEMENT.

Application filed October 14, 1918. Serial No.

To all whom it may concern.-

Be it known that we, FRANK H. JOHN- STON and JAMES C. CHRISTENS N, bothcitizens of the United States, residing at Indianapolis, in the countyof Marion and State oflndiana, have invented certain new and usefulImprovements in Pulleys and. like Elements, of which the following is aspecification.

Our invention relates to improvements in laminated pulleys, commonlyknown as friction disks and wheels, and more'particularly to hubs orcores there for and the means for'providing driving engagement betweenthe succession of laminae and the hub or core.

The object of the invention is to simplify and improve the structure ofsuch machine elements whereby they will not only be cheapened inconstruction, but will be more eflicient in operation, positive indriving action, easily assembled, and unlikely to get out of repair. I

A further object of the invention is to provide a new form of huborcore, having peripheral contact surface substantially equal to that ofthe usual form of cylindr1- cal core of equivalent size, but so shapedand arranged as to afford increased driving engagement or resistance totorsional strains.

A further object of the invention is to provide a hub or core which willtend to reduce to minimum the bursting strain or expansion of thesurrounding laminae. I

With the above primary, and other incidental objects in view as willmore fully appear in the specification, the invention consists of thefeatures of construction, the parts and combinations thereof and themode of operation, or their equivalents, as hereinafter described andset forth in the claims.

Referring to the drawings, Figure 1 is a perspective view of anassembled pulley of the sleeve type, embodying the mvention forming thesubject matter hereof. Fig. 2 is a. longitudinal sectional View thereof.Fig. 3 is a perspective view of the hubor core before being embodied intl1e pulley. Figs. 4 and 5' are diagrams indicating the relative shapesand proportions of the hub and laminae. Fig. 6 is an end view, somewhatdiagrammatic of a modification of the hub or core.

Specification of Letters Patent.

rim or sleeve may at 6. This affords at Patented Feb. 17, 1920. 258,031.

Like parts are indicated by similar characters of reference throughoutthe several views.

Laminated pulleys, known generally as paper pulleys, and friction disks,and wheels of like construction are in common use at the present time.The resent invention relates to a hub or core therefor which affordsincreased driving engagement by a series of concave faces, which may beof any desired number or extent, and further obviates the burstingstrain by affording sufficient space. into which the material of theexpand to compensate for the displacement of such material by the anglesof said core,

In constructing the pulley as shown there are employed a plurality. ofannular laminae 111 assembled side by side and cemented together oradhering one to another. Extending transversely through the laminae area series of dowels or pins 2-2 which may be of wood or metal. Thelaminae 1-1 may be of paper, card or straw board, tarred board, leather,fiber, fabric or other suitable material according to the conditions ofuse to which it will be subjected and the availability of materials.These pulleys ar usually constructed from alternating sections of strawboard and tarred board, but may be wholly of either of these materials,or other material of the character mentioned. Likewise, it is to beunderstood that the hub hereafter described is not limited to suchlaminated construction, but may be employed in a molded or otherwiseformed homogeneous body, or fiber, paper pulp, wood, or similarmaterial.

In the construction shown in Fig. l annular end plates 3 of metal areprovided which serve to protect the intermediate material, and toreceive the hammer blows incident to driving the pulley onto and 0H of ashaft. These metallic end plates 3 are attached to alternate dowel pins2 by screws 4.

The assembly of laminae is bored out concentrically, the bore beingcylindrical in form. Into this bore is pressed a hub or core 5, ofequilateral polygonal shape, the faces of which are arcuate and indentedas the juncture of adjacent arcuate faces longitudinal ridges or beads 7While the arcuate faces may beof any desired number and of anyproportionate radius in relation with the diameter of the hub, it hasbeen found by experiment that, for ordinary conditions of use, indentedarcuate faces the radius of which is equal to the maximum radius of thehub at one of the ribs or ridges 7 affords a serviceable and convenientform. This relation of the curvature of the faces to the size of the hubis best illustrated in the diagram Fig. l in which the radius AB isequal to the radius CD. The radial proportions mentioned afford anindented peripheral surface exactly equal to that of a cylinder havingthe maximum diameter A-B, indicated by the exterior dot and dash line inFig. 4:.

Throughout the drawings the hub or core has been shown as decagonal incross section, ten sides havin also been found by experiment andexperience to be a servlceable and convenient number. i

It is to 'be understood that a. greater or less number of sidesdiffering in radius from that of the hub may be used. In Fig. 6 there isshown a modification in which the hub is of hexagonal form the radius ofthe sides being much less than that of the hub, thus affording indentedfaces of greater depth. Such form of hub would be desirable in the eventmaterial of comparatively soft or yielding character is employed for therim.

In fitting the rim or sleeve to receive the hub, the rim is bored to asize intermediate the maximum and minimum diameters of the hub asindicated at 8, Figs. 4-, 5, and 6. The bore is thus of less radius thanthe maximum radius of the ridges or ribs 7, but oreater than the medialpoints of the indentations 6. The ribs 7 bite into or embed themselvesin the material of the rim or sleeve thus increasing the drivingengagement. The displacement of material is compensated for by theindentations 6 into which the material is crowded, thus completelyfilling the indented faces and mak- 1n a continuous peripheral contactwith the hub. The frictional resistance is thus materially increasedover that of a. cylindrical surface.

In Fig. 5 there is shown a modification in which the polygonal hub isshown with fiat faces as at 9. The bore of the rim or sleeve is shown at8 as greater than the diameter across the flats but less than thediameter at the angles. The overlapping of the relative shapes of thehub and bore in this figure as well as in Figs. 4.- and 6 affords aspace 10 into which the material is crowded by the angles or ridges intheir displacement of material, whether the faces be fiat or indented.

In the drawings the bore of the hub has been shown splined or recessedat 11 to received a key by which it is fixed upon a shaft. There arealso shown two set screws 12 extending through the laminated rim orsleeve and adapted to engage a shaft.

It is to be understood that the invention is not limited to pulleysofsmall size but may be applied to large wheels.

The solid hub or core may be made of any desired diameter. To saveweight and material the core or filler may comprise a rim or flangehaving the polygonal indented exterior periphery, or the succession offiat faces as mentioned, which rim or flange may be connected to acentral sleeve or hub by a series of arms or spokes similar to anordinary covered pulley, except that the latter does not have thepolygonal periphery. Such enlarged construction being obvious in view ofthe foregoing disclosure it is not necessary to be illustrated.

We are aware that polygonal hubs per se, 2 (2., square hubs, are not newin this art, but as heretofore constructed, the bore or opening in thepulley body and the hub have been accurately proportioned and shaped toagree exactly one with the other, whereas in the present instance apolygonal hub is pressed into a round hole the periphery of which isoverlapped by the angles of the hub. The form of hub above described hasthe additional advantage that the exterior of the hub Or core requireslittle or no machine operations to adapt it for use.

From the above description, it will be apparent that there is thusprovided a device of the character described. possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions,detail construction or arrangement of parts without departing from theprinciple involvedor sacrificing any of its advantages.

While in order to comply with the statute, the invention has beendescribed in language more or less specific as to certain structuralfeatures. it is to be understood that the invention is not limited tothe specific details shown, but that the means and construction hereindescribed comprise but one mode of putting the invention into efiect.and the invention is therefore claimed in any of its possible forms ormodifications within the legitimate and valid scope of the appendedclaims.

Having thus described our invention, we claim:

1. A bushing for machine elements comprising a rigid polygonal bodyhaving concave faces and a central bore, substantially as specified.

2. In an element of the character described, a main body and a rigidpoylgonal bushing inclosed therein, the faces of which are concaved.

3. In an element of the character described, a main body of yieldingmaterial,

a rigid bushing inclosed therein, aseries of longitudinal ribs upon saidbushing and recesses intermediate the said ribs into which materialforming said main body is forced to compensate for the materialdisplaced by said ribs.

4:. In an element of the character described, a main body of yieldingmaterial, and a bushing inclosed therein, said bushing having anundulating periphery, the yielding material of said body being ex pandedinto the depressions of the undulating periphery by the compression ofintermediate separate areas of material by the ridges of said undulatingperiphery.

5. The herein described method of providing bodies with bushingsconsisting in insertin within a main body of yielding materia having anopening therein, a polygonal bushing proportioned difierently from saidopening, the diameter of said opening of the main body being oneintermediate the minimum and maximum diameters of the poylgonal insert.

6. A bushing for machine elements comprising a rigid polygonal sleeve,the exterior faces of which are arcuate to a radius substantially equalto a peripheral radius of the polygonal sleeve.

7. The herein described method of constructing machine elements byforcing into an opening in an inclosing body, a polygonal insert, theangles of which overhang the periphery-of the opening, and beyond thefaces of which the opening extends.

8. The herein described method of constructing machine elementsincluding, inserting in an opening of a given shape in a main body aninsert of different shape, the dimension of which in one direction isgreater than the like dimension of the opening and the dimension ofwhich in a difierent direction is less than the like dimension of theopening, whereby the material of the inclosing body will be displacedinto registered bushing into conformity with the insert, substantiallyas specified.

9. The herein described method of pro viding bushings in bodies withoutsubjecting the body to bursting strain, consisting in forming in thebody an opening to receive the bushing, which opening is of lessdiameter than the maximum diameter of the bushing, forming said bushingwith reduced portions intermediate the points of maximum diameter, saidreduced portions being of less radius than that of the opening, andpressing said bushing within the opening, whereby the material of thebody will be expanded into close engagement with the reduced portions ofthe bushing to compensate for the displacement of material by thosepoints of the bushing of maximum diameter.

10. The herein described method of providing bushings in bodiesconsisting in forming an opening in the body to receive the bushing, soproportioning and positioning the bushing and opening in relation onewith the other that the periphery of the bushing will extend beyond theopening at spaced intervals, and the opening will ex tend beyond theperiphery of the bushing at intermediate points, and pressing the unsuchopening whereby the material displaced by the overlapping portions ofthe bushing will be compensated for by the expansion of the material ofthe body at those points at which the opening initially extends beyondthe periphery of the bushing.

In testimony whereof, we have hereunto set our hands this 17th day ofAugust A. D. 1918.

FRANK H, JOHNSTON.

AMES J. CHRISTENSEN. Witnesses:

C, L. Conn, S. A. CLINCHENS.

